Recently, profiles (also called sections or section bars) made from aluminum alloy or steel-plastics have been widely used in the building material area. Especially, they have been utilized to fabricate most of door and window frames of buildings instead of the wood or steel. A technical issue on how to connect parts of the profile naturally arises.
Current profiles have been made by welding or inserting parts thereof. For example, a steel profile can be made by welding parts thereof, an aluminum alloy profile can be manufactured by welding or connecting parts thereof, and steel-plastic profile can be fabricated by welding parts thereof. However, in a practical fabrication or installation process, although the flatness of the profile is good, there are some defects such as lower accuracy of its shape, inconvenience of assembling, and difficulty in fabricating on the spot after the profiles are cut to form a frame. Further, since a deformation of the profile will occur after it is used for a period of time, it is not convenient to disassemble the profile for maintenance thereby causing a waste. Therefore, there is a need to solve the problem of connecting parts of the profile.